Genital Warts: Conventional Treatment Approaches
The primary goal of conventional treatment is to remove visible symptomatic warts. Most patients respond to conventional treatment with wart-free periods. Without treatment, warts will spontaneously resolve, remain unchanged, or grow in size or number. The factors influencing these outcomes are not known. The main benefit of treatment is symptom improvement. A secondary likely benefit of treatment is the reduced risk of infectivity and decreased likelihood of complications associated with human papillomavirus infection. Current conventional treatment options do appear to reduce human papillomavirus DNA and thus infectivity. However, successful treatment of genital warts does not eradicate infectivity or the risk of recurrences of the disease. There are several standard, accepted conventional treatments.
Determination of the type of treatment is made after evaluation of wart size, location, morphology, patient preference, cost of treatment, adverse effects, and provider preference. Generally, a course of applied treatments is required to remove genital warts. First-line therapy for human papillomavirus may consist of the application of 0.5% podophyllotoxin (Podofilox 0.5% solution or gel) one to four times. Podophyllotoxin is an antimitotic agent. This treatment has been shown to be effective in 70% to 90% of men or women with exposed and accessible genital warts. This treatment is typically well tolerated and self-administered, and produces minimal local irritation. Ten to twenty percent podophyllin resin ethanolic solution has also been used topically. However, podophyllin resin is less effective than podophyllotoxin. In one study, 94% of patients treated with podophyllotoxin were cured versus only 29% of patients treated with podophyllin resin. Additionally podophyllin resin is commonly associated with local inflammation, erosion, pain, and burning. Finally, concern exists about the systemic absorption of the podophyllin resin and its systemic toxicity, particularly in pregnant women.
An alternative to podophyllotoxin is topical application of trichloroacetic acid (TCA) or bichloracetic acid (BCA). Trichloroacetic acid and bichloracetic acid are caustic agents that coagulate proteins, thus destroying the wart. A health care provider applies these agents. Treatment is repeated weekly until the lesions resolve. This treatment is generally effective but can cause inflammation at the site of application. If pain develops, soap or sodium bicarbonate must be applied to neutralize the acid.
Cryotherapy is another common treatment for exposed genital warts. Cryotherapy with liquid nitrogen or cryoprobe is typically done weekly or biweekly. Cryotherapy causes thermal-induced cytolysis. This therapy can be quite effective if applied properly; however, overtreatment can cause localized pain and blistering. Conversely, undertreatment is ineffective. Typical second-line therapeutic interventions include surgical removal of warts. There are several techniques of surgical removal. All techniques require local anesthesia. Surgical removal is a one-time treatment. However, surgery is more expensive and requires more time than medical treatment options. Surgical treatment of genital warts is usually reserved for patients with a large number of lesions or for patients who have not responded to other treatments. Another second-line therapy is the intra-lesional injection of interferon. Many trials have confirmed the efficacy of this treatment. It causes the disappearance of all visible warts in approximately 43% of patients and visibly shrinks visible warts in an additional 25%. However, interferon therapy is expensive and requires three treatments each week, usually for 4 to 6 weeks.
All conventional treatments are somewhat limited in their efficacy. In order to increase efficacy, it is common for health care providers to use combination therapy. However, combination therapy increases adverse effects. For this reason, some providers prefer to use different therapies sequentially. Warts that are not easily accessible, such as those located on the cervix, in the anal canal, or in the urethral meatus, are more difficult to treat. Liquid nitrogen or trichloroacetic acid (or bichloracetic acid) are common treatments for warts located in these areas. Cervical warts must be closely monitored and high-grade squamous intraepithe-lial lesions (HGSIL) must be excluded before treatment for warts is begun. An important and universal aspect of the treatment of any type and location of genital warts is to examine and treat the sexual partners of the patient. In addition, women with genital warts should receive STD and Pap screenings annually until normal Pap tests have occurred for 36 consecutive months after treatment. After this time, a woman may elect to receive Pap screenings every 36 months. Women who are found to have human papillomavirus but who do not have any visible warts are not candidates for treatment as there are no treatments that are known to eradicate the infection. These women should, however, obtain annual Pap screenings. Additionally women with a Pap test indicative of low-grade SIL or ASCUS should obtain human papillomavirus DNA testing. If high-risk types of human papillomavirus DNA are found, these women should have colposcopy and biopsy to assess for more extensive dys-plasia. Gardasil, an human papillomavirus vaccine, has recently been released and is recommended for women ages 14 to 26 years of age for the prevention of human papillomavirus infection, and thus is expected to lower cervical dysplasia and cervical cancer rates.
